Spring



(No Modem 3 Sheets-Sheet 1.

J. W. CLOUD.

SPRING.

Patented Jan. 1, 1895.

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JOHN WILLS CLOUD, OF CHICAGO, IlilllNOlS.

SPRING.

SPECIFICATION forming part of Letters Patent 0; 533,910, dated January 1 1895. v

. Application filed Jnnc'l. 1894- Serisl No. 513.7421 (i lomodohg I less sudden or violent than. that of the ordinary helical sprin i To this end, my invention, generally stated, consists in the combination of a main-spring, and an auxiliary or controlling spring, connected with, and having an initial strain acting in opposite direction to, the main spring.

The improvement claimed is, hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a. vertical, longitudinal, central section through a spring embodying my invention;

liig. 2,sloot-tom plan View of the some; Fig.

3, a. face view of.the lower end of the rod or bar of which thenugtiliary spring is formed; Fig. 4, a side View of the lower end portion of said rod or her; Fig. 5, a vertical, longitudinal, central section through espring illus-v trating another form of my improved spring; Fig. 6, stop plan view of the some; Figs. 7, 8 end 9, vertical, longitudinal, central sections through other formsof springs embody ing my invention; Fig. 10, a. plenview of a construction \in which a. singleauxiliary or controlling spring is combined with a. host or group of four main springs; Fig. 11, a vertical longitudinal central section through the same; Fig. 12, a. plan of a construction in which four main and four auxiliary springs, of the character of those shown in Figs. 1 to 4 are employed, and Figxfll, 9, vertical section through the same at the line as, agfof Fig. 12.

In the practice of my invention, referring first to Figs. 1 to 4 inclusive, I provide a compound spring, consisting of a, main helical spring 1, and an auxiliary or controlling spring 2,which is originally coiled to the same pitch as that of the main spring, when the coils of said main spring are brought to.-

gether or closed down one open the other under compression, and is connected with the main spring by being screwed into the coils thereof, when said coils are closed tendegree greater than that due to the normal tension of the main spring, end, preferably, to or near the limit of compression of themain spring. Upon the release of the main spring 1, from the compression by which its coils have been closed down,-it returns to an ope'rative position, in which its-height is less 7 than when originally coiled, by reason of the resistance of the auxiliary or controlling spring 2, which is pnt under initial tensional strain by the opening or separation of the coils of the released main spring, and which, therefore, acts in opposition to the expansionor opening tension of the main spring, Under such construction, it will be: seen that the initial strain, in this case tensionel, impsi-ted te'the spring 2,-scts inopposite direction to the tension of the spring 1, ths7t is to say, proportionately tothe loading, sndcompression under load, of the spring 1, the'tension' of the spr ng is reduced, and saidspringZ, -therefore,scts, in conj unction'with the load, to compress the spring 1. Conversely, the tension of the spring 2 is increased, proportionstely to the unloading, end expsnsion tinder and free from snddenness or violence in 'recoil, and the springis made specially desir able for use on electric and other street rail: road cars, or for ,passengercer equalizing springs-or freight cor bolster springs. As shown in Figs. 33nd 4, the rod 4 forming the auxiliary orcontrolling spring- 2, niey, ifdesired, lie-brought. to a flattened or taper form in cross section at and toward its ends, toincreese the hearing ne'er the ends of the spring 2 on the coils of the main spring 1; The main spring 1 should also he tapered toward its sdjscent'ends, as indicated in 2, to fecilitste screwing in the spring 2;

I Figs. and 6 illustrate another form of my improved spring, in which, while the same relation and the same action of the springs 1 and-'2 are presented and attained asi'in the the former case, but goes freely inside of said spring, and is given its initial strain by being elongated and connected by caps 3, 3, to the end plates t, 4:, of said spring 1. The caps 3, 3, are grooved circumferentially, to engage operative feature of my invention.

the ends of the springs 2,'and pass freely through openings 5, 5, in the end plates 4., 49. The spring 2 is elongated until its .upper cap 3 is raised above the upper end plate 4, when by giving the cap a quarter turn, the spring 2 is held under initial tension, and acts, in connection with the spring 1, in the manner above described.

Figs. 7, 8, and 9 show further modifications of form, all embodying the same essential The auxiliary or controlling spring 2 is, in these instances, normally compressed, instead. of extended as in the cases previously described, but in service, inversely varying stresses are produced in the two springs, as in the prior cases. Initial strain, in this case compressive, is imparted to the spring 2, by means of a cap 6 and bolt 7, through which the spring 2, after having been compressed to the desired degree, is connected with the lower end plate t of the main spring'l. The spring 2 bears,.at its upper end, on its cap G,'and, at its lower end, on the upper end plate 4 of the main spring 1, which may, in order to enable the height of the compound spring to be rednced as far as practicable, be formed with a downwardly extepdiug gylindrical body or frame 8, havingat its lower end a bearing for the spring 2.

As shown in Fig. 7, the spring 2 does not project above the end of the spring 1, but does so project, in operation, in the constructions of Figs. 8 and 5), so that'an opening must be provided for it, in the bolster or other member 9, supported by the spring.-

Fig. 9 shows the spring'2 as located entirely above the spring 1, thus enabling a more powerful auxiliary or controlling spring to be employed than can-be placed inside an ordinary coil.

Figs. 10 and 11 illustrate a construction in which a single auxiliary or controlling spring 2 is employed in combination with a nest or group of four main springs, 1, 1, 1, 1. As in the springs of Figs. 7, 8, and 9, initial compressive strain, inducing tensional action in opposition to the tension of the main springs, is imparted to the spring 2, and is transmitted therefrom to the springs l, 1, 1, 1, through a cap 6, bolt 7, lower end plate 4, and upper end plate 4, having a downwardly extending body or frame 8 with a bearing for the spring 2 at its lower end, as in Figs. 7 and 8 Figs. 12 and 13 show a nest or grgup'" of four compound springs, each composed of a main spring l and an auxiliary or controlling spring 2, screwed into the main spring and normally under initial tension, as in the case of the spring shown by Figs. 1 to 4, inclusive.

It will be obvious that other structural applications, involving the essential feature and operative principle of my invention, may be made by th se skilled in the art without involving fl departure from the spiritof my invention, and I do not therefore desire to limit myself to the specific exemplifications selected for illustration herein.

I claim as my invention and desire to secure by Letters Patent 1. The combination of a main'spring, and an auxiliary or coutiolling spring connectedto the main spring under an initial strain acting in opposition to the main spring, substan' tially as set forth.

.2. Thecombination ofamainspringandan auxiliary or controlling spring which is ini- .tially strained by connection with the main spring, so as to act in opposition thereto, substantially as set forth.

3. The combination ofa main spring,and an auxiliaryor controlling spring connected to the main spring under an. initial strain acting in oppisition to the main spring with a varying resistance, substantially as set forth.

4. The combination of a main spring, and an auxiliary or controlling spring connected to themain spring under an initial strain which increases or decreases coincidently with the 'decrease or increase, respectively, of strain on the main spring substantially as set forth.

5. The combination of a main spring, an auxiliary or controlling spring which is initially straincd'by connection with the main spring so as to act in opposition thereto, and a bolster or other member through which a resistance is applied to the main spring, substantially as set forth.

6. The combination, in a compound spring, of a series of main springs, and an auxiliary or controlling spring which is initially strained by connection with each of the series of main springs, so as to act in opposition thereto, substantially as set forth.

7. The combination of a main spring and an auxiliary or controlling spring which is screwed into the coils of the main spring when said coils are closed to a degree greater than that due to the normal tension of the main spring, so that the auxiliary or controlling spring shall be under an initial strain acting in opposition to the main spring, substantially as set forth. JOHN \VILLS '(JLOUl). Witnesses:

Josnrn W. TAYLOR, A. J. S nnvnns. 

